The Conception Calculator

Due Date June 6: When Did You Conceive?

Due dates & conception. Updated . Calculated with the standard pregnancy dating method used by ACOG and the NHS.

If your baby is due on June 6, conception most likely happened around September 13 of the previous year. Here is how that date is worked out and the range of days it could realistically fall on.

Key dates for a June 6 due date

Most likely conception dateSeptember 13
Likely conception windowSeptember 10 – September 16
Days when sex could have led to pregnancySeptember 8 – September 14
Estimated first day of last periodAugust 30
Positive home test likely fromSeptember 27 (around the missed period)
Second trimester begins (14 weeks)December 6
Third trimester begins (28 weeks)March 14
Full term begins (39 weeks)May 30

How the conception date is calculated

Due dates are normally counted as 280 days (40 weeks) from the first day of the last menstrual period. In a typical 28-day cycle, ovulation and conception happen about two weeks after that period starts, so conception sits roughly 266 days before the due date. Subtracting 266 days from June 6 gives September 13.

Sperm can survive in the reproductive tract for up to five days, while an egg lives for about 12 to 24 hours after ovulation. That means sex several days before ovulation can still lead to pregnancy.

How certain is this date?

Only a small share of babies, often quoted at around 4 to 5 percent, arrive on their exact due date, so dates worked backwards from a due date carry a margin of a few days either way.

If your cycles are usually longer than 28 days, conception probably happened a little later than September 13; with shorter cycles, a little earlier. A cycle that is 32 days long, for example, shifts the likely date about four days later.

Check your own dates

Enter your exact due date in the conception date calculator to see these results with weekdays and the correct year, or start from your last period with the last-period conception calculator.

Conception Date Calculator: Find the most likely conception date from your due date.

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This article is general information, not medical advice. Talk to a doctor or midwife about your own pregnancy or fertility.